AFAIK when regening you create AC power from the AC motor something converts it into DC and puts it back into the battery. However batteries need a charger in between to get the current and voltage they want. It also takes a while for the battery to communicate with the EVSE when charging. With regen it is instantaneous. How does regen do that? When regenning the current you put in to the battery depends on your speed and how hard you're regenning. My EV for example only has a 4kW on board charger but I'm pretty sure it regens way above 4kW when slowing down. Can anyone explain how it works?